Hitachi, Ltd.

Motoki Obata

Hiroyasu Nishiyama

Masahiko Adachi

Koichi Okada

Kei Nakajima

Takuma Nagase

Koji Doi

A computer includes a storage region in which an object generated by executing a program is disposed, and a control unit that performs execution of the program and releasing of the storage region. The control unit updates time information using garbage collection, a capacity of objects in a memory, or similar as a trigger, acquires information of a program generating an object and time information at the time of generation of the object which are recorded in a recording device so as to be correlated with each other when the object is generated. The control unit further detects an object which is unnecessary to execute a subsequent program and acquires the time information, and records a difference between the time information at the time of the generation and at the time of the detection in the recording device so as to be correlated with the information of the program.

Computer, control method of computer, and recording medium

A method of managing a memory in a computer system including a processor executing programs and the memory, the memory including a first area, which is managed by a garbage collector, and a second area, which is not managed by the garbage collector, the method including the steps executed by the processor of: checking a reference relation of basic point data associated with the second area by tracing references from the basic point data; when the reference relation of the basic point data has a structure including a reference to data belonging to the same class as the class of the basic point data, determining that particular data out of data constituting the structure is prohibited from being migrated to the second area; and migrating data stored in the first area out of data remaining after excluding the particular data from the data constituting the structure to the second area.

Method of managing memory in computer system, computer system and memory managing program

It is provided a memory management method for releasing an unnecessary area in a memory area used by a program stored in the memory and executed by the computing device. The memory management method including the step of: setting in the memory, a first memory area which is used to execute the program; setting in the memory, a second memory area which can be operated by the program; setting a utilized area in the second memory area based on an instruction from the program; storing objects including data in the utilized area of the second memory area based on an instruction from the program; determining whether the program uses the objects stored in the utilized area within the second memory area; and releasing, by the computing device, the utilized area occupied by an object that is not used by the program among the objects stored in the utilized area.

Memory management method, computer system and computer readable medium

A memory management method is provided to manage a memory in which areas of a garbage collected Java heap memory and a non-garbage collected external heap memory can be secured, by using a program executed by a processor in a computer. If it is judged that there is no reference to all data arranged in the external heap memory or starting point data of reference relations included in the all data, from data arranged outside the external heap memory, then the external heap memory is judged to be capable of being deallocated. As a result, it becomes possible to implement memory management in which garbage collection needing a long time program stop is not conducted and an additional API is not used.

Memory management method and computer

Memory management by garbage collection involves a memory area that is allocated in a computer. Data is created in the memory area in accordance with a program executed by a processor of the computer, and it is checked whether or not data necessary to execute the program exists in the memory area to be released, in response to an explicit instruction to release the memory area. As a result of the check, if data necessary to execute the program does not exist in the memory area, the memory area is released. As a result of the check, if data necessary to execute the program exists in the memory area, the data is moved to a memory area different from the memory area to be released.

Memory management method and computer using the method

The present invention provides a memory management method, including the steps of: securing a memory area by a program executed by a computer; storing an object in the memory area in accordance with the execution of the program; bringing the memory area into a release reservation state in accordance with the program instructing the memory area to be released; moving the object to a memory area not to be released while another object in the memory area not to be released and not to be brought into the release reservation state refers to the object in the memory area to be released including the memory area to be brought into the release reservation state; and releasing the memory area to be released.

Memory management method and computer using the same

With regard to a plurality of data stored in a memory, relationship of data is grasped twice after a time interval therebetween. Next, increased data C, E, Ewhich are not present in data of a first time are extracted from data of a second time, and weights '1', '2', &#x201c;2&#x201d; in accordance with data sizes are attached to the increased data. Next, the weights are successively propagated from a lower order data of a destination of reference to a higher order data of a source of reference successively. When there are a plurality of lower order data E, Efor a higher order D, a weight constituted by adding the weights &#x201c;2&#x201d;, &#x201c;2&#x201d; of the plurality of lower data E, Eis made to be a weight &#x201c;4&#x201d; of the higher order data D, and the weights of the respective data represent leak scores which causes memory leak.

Method of detecting memory leak causing portion and execution program thereof

Under program execution environment, a file size of a heap dump is reduced which is acquired so as to detect memory leaks, and so as to investigate occurrence causes of the memory leaks. In order to provide a memory leak investigating means which can be used even in a large-scaled system, the below-mentioned heap dump acquiring method is provided: When a heap dump is acquired, only such an object within objects stored in a heap memory is outputted which is adapted to the following conditions: That is, in a condition (1), an object exists among objects which are newly produced within a designated time period, and in another condition (2), an object is present on a reference path defined from a root set to the object which satisfies the above-explained condition (1).

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Toda, Japan

Motoki Obata